应用程序显示一些不相关的文本而不是 Textview

Question

我正在开发一个 android 应用程序，在我将 textview 添加到主 activity 布局之前它工作正常。

正在显示所有图像。但是显示屏上显示的不是 textview，而是一个不相关的内容。下面是来自 mainactivity.java.

的代码

import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.InputType;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;

public class MainActivity extends AppCompatActivity {

ImageButton showBalDialog, showExpDialog, showIncomebtn, showExpbtn;
TextView bal_dialog, total_incomes;

public static final String DB_name = "mydb";

DatabaseHelper m_db;

private String amnt, src, exp, rzn;

private String incomes = "sum";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    m_db = new DatabaseHelper(this);

    showBalDialog = findViewById(R.id.btnshowBalDialog);
    showExpDialog = findViewById(R.id.btnshowExpDialog);
    showIncomebtn = findViewById(R.id.btnshowIncomes);
    showExpbtn = findViewById(R.id.btnshowExpenses);
    total_incomes = findViewById(R.id.totalincomes);

    incomes = String.valueOf(total_incomes);
    total_incomes.setText(incomes);
 }
}

下面是来自activity_main.xml

的代码

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
 xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:screenOrientation="portrait"
android:layout_height="match_parent"
tools:context=".MainActivity">



<ImageButton
    android:id="@+id/btnshowBalDialog"
    android:scaleType="fitXY"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_marginStart="20dp"
    android:layout_marginTop="40dp"
    android:cropToPadding="false"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    android:background="@drawable/add_inc"> // this is the image(eye)
</ImageButton>

<ImageButton
    android:id="@+id/btnshowExpDialog"
    android:scaleType="fitXY"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_marginEnd="20dp"
    android:layout_marginTop="40dp"
    android:cropToPadding="false"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    android:background="@drawable/add_exp"> // this is the image(eye)
</ImageButton>

<ImageButton
    android:id="@+id/btnshowIncomes"
    android:scaleType="fitXY"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_marginStart="20dp"
    android:layout_marginTop="40dp"
    android:cropToPadding="false"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@id/btnshowBalDialog"
    android:background="@drawable/income_his"> // this is the image(eye)
</ImageButton>

<ImageButton
    android:id="@+id/btnshowExpenses"
    android:scaleType="fitXY"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_marginEnd="20dp"
    android:layout_marginTop="40dp"
    android:cropToPadding="false"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toBottomOf="@id/btnshowExpDialog"
    android:background="@drawable/expense_his"> // this is the image(eye)
</ImageButton>

<TextView
    android:id="@+id/totalincomes"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:layout_marginTop="20dp"
    android:text="TextView"
    app:layout_constraintTop_toBottomOf="@id/btnshowIncomes"
    app:layout_constraintStart_toStartOf="parent">
</TextView>
 </android.support.constraint.ConstraintLayout>

下面是我在应用程序图形用户界面上得到的而不是 Textview。

Answer 1

total_incomes 是 Textview，您将 TextView 与 xml 中存在的 R.id.totalincome 绑定。

incomes = String.valueOf(total_incomes);
total_incomes.setText(incomes);

您正在获取 total_incomes 的字符串值并将其存储在 incomes 中，与您在 total_incomes。所以简而言之，您正在设置文本视图 ID。

Answer 2

你必须这样做：

total_incomes.setText(incomes);

您的收入值已经在字符串中，无需使用 String.valueOf()

而不是

incomes = String.valueOf(total_incomes);
    total_incomes.setText(incomes);

应用程序显示一些不相关的文本而不是 Textview

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